The present invention relates to a welding contact tip for use on a welding torch of a consumable electrode type arc-welder.
A known welding contact tip (simply referred to as "tip" hereinafter) will be described with reference to FIG. 1. The tip 5 has a central wire passage bore 3 through which a consumable electrode (simply referred to as "welding wire" hereinafter) is fed to a welding region. In addition, the tip supplies welding electric current to the wire. Thus, the tip has a double role: Namely a role of a guide for guiding the wire and a role of electric power feeder.
In order to supply welding current to the wire, the tip 5 is held in contact with the wire. During welding, a high temperature is developed on the portion of the tip 5 contacting the wire. In consequence, the wall of the wire passage bore 3 is so heavily worn that the tip is soon disabled to conduct the double role, i.e., the tip fails to guide the wire and to supply welding current.
Hitherto, therefore, expensive chromium-copper alloys having superior wear resistance at a high temperature have been used as the material of the tips.